Seeing Mayor Gavin Newsom on the national stage with former president Bill Clinton on Monday night is a reminder of how political winds can change. On the eve of the biggest night of the presidential primaries, Newsom shared the spotlight during a town hall meeting staged and broadcast on cable TV and satellite radio by the Hillary Rodham Clinton campaign.

But just four years ago, current Democratic presidential candidate Barack Obama is said to have declined to have his picture taken in San Francisco with Newsom, who was then at the center of a national uproar over his decision to allow same-sex marriage in San Francisco.

"I gave a fundraiser, at his (Obama's) request at the Waterfront restaurant," said former San Francisco Mayor Willie Brown. "And he said to me, he would really appreciate it if he didn't get his photo taken with my mayor. He said he would really not like to have his picture taken with Gavin."

Today, of course, Obama's people are backpedaling away from that account like crazy. His deputy campaign director, Steve Hildebrand, who lives with his partner as an openly gay man, calls it "a ridiculous story."

"Barack Obama gets his picture taken with gay people all the time," Hildebrand said. "Including me, his deputy campaign manager."

But insiders at City Hall, both current and former members of Newsom's staff, recall the incident well. And you can bet that Newsom hasn't forgotten it either.

"He was pissed," said one former staffer.

In fact, early last year, Newsom alluded to the incident in an interview at the World Economic Forum in Davos, Switzerland. Speaking to Reuters on Jan. 26, 2007, Newsom was asked about three potential Democratic candidates: Obama, Hillary Clinton and Al Gore.

He was asked about the flak he took after announcing that San Francisco would allow same-sex marriages - flak that included claims he had helped Republicans by handing them a wedge issue heading into a presidential election year. In the interview, Newsom admitted he'd been hammered over the decision. "And I'm not just saying from Republicans," he added at the time.

"One of the three Democrats you mentioned as presidential candidates, as God is my witness, will not be photographed with me, will not be in the same room with me," Newsom told Reuters, "even though I've done fundraisers for that particular person - not once, but twice - because of this issue."

Now, could that be why Newsom declared his support for Hillary Clinton a good six months ago? San Francisco SupervisorBevan Dufty, who was concerned enough about the 2004 story to look into it, insists the mayor's endorsement of the former first lady is more likely a case of repayment of political favors. And Newsom said after the town meeting that the snub "had nothing to do with my decision."

But Brown, as savvy as they get when it comes to reading political motivations, thinks the 2004 snub played a part.

"I think he has harbored this resentment for years," Brown said of Newsom, adding that Obama was reluctant to be seen appearing in San Francisco altogether, much less side by side with the gay-marriage mayor. "I would guess that is part of the rejection of the Obama campaign."

Though same-sex marriage is still a hot-button issue in 2008, it is no longer the shocker that had the country in an uproar four and five years ago. Until you go back and look at the news stories from those days, it is easy to forget how radical and unpopular Newsom's stand was.

And, no, it wasn't just the right-wingers who were upset. It was Democrats, too, particularly those running in the presidential primary. John Kerry, for example, was careful to stage his Bay Area appearances in Oakland, not San Francisco, after the controversy hit.

"I don't know anybody in the party who was happy with him, except me," Brown said. "He was all alone out there. He was the poster child for same-sex marriage worldwide."

That's why Brown says he doesn't blame Obama for his caution. Today, of course, the Illinois senator is happy to embrace gay causes. But in 2004, nationally, same-sex marriage was a radical notion.

"What they ought to say is, 'Damn right I did it, and I'd do it again,' " Brown said of the Obama camp. "He was in a race for the Senate, and I am guessing that downstate Illinois is a pretty red (meaning conservative) group of voters."

But on the eve of the biggest vote of the primaries - with the big prize of a California win at stake - the Obama campaign isn't taking Brown's advice.

"They could attack Obama for a lot of things, but this isn't one of them," said Hildebrand. "And for this to pop up on the eve of the election is very suspicious. There's just no truth to it."

To which Brown replies, "Why would I make it up?"

It seems clear that something happened. Staffers say there is still a chill between the two, although Monday night Newsom gave Obama his qualified support.

"I believe in his leadership qualities, and I look forward to voting for him," Newsom said.